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In average there is one defect per 100 m of magnetic tape. (a) What is the probability that 150 m of tape have no defect? (b) Given that the first 100 m of tape had no defect what is the probability that the whole 150 m have no defect? (c) Given that the first 100 m of tape had at least one defect what is the probability that the whole 150 m have exactly two defects?

difficulty advanced
 Mar 21, 2015

Best Answer 

 #3
avatar+33615 
+5

So how about:

 

 Poisson:

.

 Mar 21, 2015
 #1
avatar+118608 
0

I do not know how to get the initial probabiliy for this one.  Can anyone help?

 Mar 21, 2015
 #2
avatar+33615 
+5

Try using the Poisson distribution Melody.

The probability of exactly k defects/unit interval, given an average of λ defects/unit interval is given by:

 

$$p(k;\lambda)=\frac{\lambda^ke^{-\lambda}}{k!}$$

.

 Mar 21, 2015
 #3
avatar+33615 
+5
Best Answer

So how about:

 

 Poisson:

.

Alan Mar 21, 2015

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